下列化合物氢化热最低的是()。
A.1,3-戊二烯
B.1,4-戊二烯
C.1,3-丁二烯
参考答案:C
—What did you see when you came into Simon's room?
—I saw he _____ the Internet. [ ]
A. was searching
B. searched
C. search
D. will search
患者,24岁,长期进食酸甜食物时右下后牙不适。查:右下67合面龋洞,探质软,中等深,稍敏感,冷水进洞后稍敏感,该患牙应诊断为()。
A.浅龋
B.中龋
C.深龋
D.可复性牙髓炎
E.慢性牙髓炎